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Related papers: Neutron stars in Einstein-$\Lambda$ gravity: the c…

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Neutron stars are one of the most extreme objects in the universe, with densities that can exceed those of atomic nuclei and gravitational fields that are among the strongest known. Theoretical and observational research on neutron stars…

High Energy Astrophysical Phenomena · Physics 2023-03-16 J. Alfredo Collazos

The realistic models of neutron stars are considered for simple $R+\alpha R^2$ gravity and equivalent Brance-Dicke theory with dilaton field in Einsein frame. For negative values of $\alpha$ we have no acceptable results from astrophysical…

General Relativity and Quantum Cosmology · Physics 2018-12-27 Artyom V. Astashenok , Alexey S. Baigashov , Sergey A. Lapin

We numerically construct compact stars in the scalar-tensor theory of gravity with non-minimal derivative coupling of a scalar field to the curvature and nonzero cosmological constant. There are two free parameters in this model of gravity:…

General Relativity and Quantum Cosmology · Physics 2025-04-08 P. E. Kashargin , A. A. Lebedev , S. V. Sushkov

We investigate how current and proposed observations of neutron stars can lead to an understanding of the state of their interiors and the key unknowns: the typical neutron star radius and the neutron star maximum mass. A theoretical…

Astrophysics · Physics 2008-11-26 James M. Lattimer , Maddapa Prakash

The observable macroscopic properties of relativistic stars (whose equations of state are known) can be predicted by solving the stellar structure equations that follow from Einstein's equation. For neutron stars, however, our knowledge of…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Lee Lindblom

In this paper, we present a new hydrostatic equilibrium equation related to dilaton gravity. We consider a spherical symmetric metric to obtain the hydrostatic equilibrium equation of stars in $4$-dimensions, and generalize TOV equation to…

General Relativity and Quantum Cosmology · Physics 2015-07-27 S. H. Hendi , G. H. Bordbar , B. Eslam Panah , M. Najafi

We investigate the properties of the neutron star with relativistic mean field models. We incorporate in the quantum hadrodynamics and in the quark-meson coupling models a possible reduction of meson masses in nuclear matter. The equation…

Nuclear Theory · Physics 2007-05-23 C. Y. Ryu , C. H. Hyun , S. W. Hong , B. K. Jennings

The properties of neutron star are studied in the framework of relativistic Hartree-Fock (RHF) model with realistic nucleon-nucleon ($NN$) interactions, i.e. Bonn potentials. The strong repulsion of $NN$ interaction at short range is…

Nuclear Theory · Physics 2019-10-28 Ying Zhang , Peng Liu , Jinniu Hu

Within the framework of Einstein-Gauss-Bonnet theory in five-dimensional spacetime ($5D$ EGB), we derive the hydrostatic equilibrium equations and solve them numerically to obtain neutron stars for both isotropic and anisotropic…

General Relativity and Quantum Cosmology · Physics 2024-10-15 Juan M. Z. Pretel , Ayan Banerjee , Anirudh Pradhan

We present a systematic investigation of the cosmological constant effects in compact stars interiors in the framework of Einstein's gravity. Consideration of a cosmological constant $\Lambda$ in compact stars is motivated by the mechanism…

High Energy Astrophysical Phenomena · Physics 2019-02-05 Noshad Khosravi Largani , David E. Alvarez-Castillo

We study static, spherically symmetric, self-gravitating systems minimally coupled to a scalar field with U(1) gauge symmetry: charged boson stars. We find numerical solutions to the EinsteinMaxwell equations coupled to the relativistic…

High Energy Astrophysical Phenomena · Physics 2013-08-05 Daniela Pugliese , Hernando Quevedo , Jorge A. Rueda H. , Remo Ruffini

Neutron stars provide a natural laboratory for studying the properties of dense nuclear matter under extreme conditions. In this proceeding, we review our current understanding of dense isospin symmetric and asymmetric matter and neutron…

Nuclear Theory · Physics 2025-04-01 Rajesh Kumar , Veronica Dexheimer , Johannes Jahan

The masses and radii of neutron stars are discussed in general relativity and scalar-tensor theory of gravity and the differences are compared with the current uncertainties stemming from the nuclear equation of state in the relativistic…

General Relativity and Quantum Cosmology · Physics 2019-07-16 F. J. Fattoyev

We complete our previous investigation concerning the structure and the stability of "isothermal" spheres in general relativity. This concerns objects that are described by a linear equation of state $P=q\epsilon$ so that the pressure is…

Astrophysics · Physics 2009-11-13 Pierre-Henri Chavanis

As current and future experiments probe strong gravitational regimes around neutron stars and black holes, it is desirable to have theoretically sound alternatives to general relativity against which to test observations. Here we study the…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Christopher Eling , Ted Jacobson , M. Coleman Miller

The macroscopic model is formulated for a neutron star (NS) as a perfect liquid drop at the equilibrium. We use the leptodermic approximation $a/R\ll 1$, where $a$ is the crust thickness of the effective NS surface (ES), and $R$ is the mean…

Nuclear Theory · Physics 2025-08-07 A. G. Magner , S. P. Maydanyuk , A. Bonasera , H. Zheng , T. Depastas , A. I. Levon , U. V. Grygoriev

In this paper, we explore the properties of white dwarfs with the modified TOV equation in Einstein-$\Lambda$ gravity, the equilibrium configurations predict a maximum mass limit for white dwarfs same as the Chandrasekhar limit when we…

General Relativity and Quantum Cosmology · Physics 2019-02-27 H. L. Liu , G. L. Lü

Neutron stars are valuable laboratories for the study of dense matter. Recent observations have uncovered both massive and low-mass neutron stars and have also set constraints on neutron star radii. The largest mass measurements are…

Nuclear Theory · Physics 2013-05-16 James M. Lattimer

Following an earlier analysis which examined the effect of the self-gravity of pressure on big-bang nucleosynthesis (BBN), we explore the effect of pressure's self-gravity on the structure of neutron stars. We construct an ad hoc…

Astrophysics · Physics 2008-06-05 Josiah Schwab , Scott A. Hughes , Saul Rappaport

We formulate the equations of equilibrium of neutron stars taking into account strong, weak, electromagnetic, and gravitational interactions within the framework of general relativity. The nuclear interactions are described by the exchange…

Solar and Stellar Astrophysics · Physics 2012-06-01 Riccardo Belvedere , Daniela Pugliese , Jorge A. Rueda , Remo Ruffini , She-Sheng Xue